Test: Check function for larger numbers

src/test/java/CalculationsTest.java

@@ -16,5 +16,8 @@ public class CalculationsTest {
         // Test with zero
         assertEquals(0, calc.calculateSquare(0));
 
+        // Test with a large number
+        assertEquals(1000000, calc.calculateSquare(1000));
+
     }
 }